The invention relates to a segmented component as well as a gas turbine having this type of component.
Gas channels are arranged between the turbo engines of a gas turbine. In the regions of a turbine in which no cooling is required, e.g., in the compressor area and at the outlet of a low-pressure turbine, these gas channels are often an integral constituent part of a housing. Examples of this are, for instance, a compressor center frame or turbine exhaust casing. In the range of high-operating temperatures, these gas channels are often segmented for mechanical reasons. Especially support structures, so-called hot struts or mid-turbine frames, which are arranged between the turbines in which structural struts, supply lines and the like cross the flow of hot gas, must be protected from high temperatures that prevail in the gas channel when the gas turbine is in operation. Normally the gas channels in this case are formed of segmented covering parts, so-called fairings, and/or gas channel wall parts or so-called panels. The outside of these segmented components is surrounded by cooling and/or sealing air. This cooling and sealing air has a higher pressure than the hot gas located in the gas channel. This makes it possible to prevent hot gas from the gas channel from escaping through gaps between the component segments to the outside. Instead, because of its higher pressure, the cooling and/or sealing air flows through the leakage points into the gas channel through which hot air flows.
In order to keep the consumption of cooling and/or sealing air as low as possible, seal devices are provided at the leakage points, e.g., the edges of the component segments, which seal the gap between the component segments. In this case, various embodiments of these sealing devices are known from the prior art. A schematic lateral sectional view of a component 2, known from the prior art, is illustrated in FIG. 1, wherein the component 2 includes a sealing point of a gas channel of a gas turbine. The component 2, which is configured as a covering (fairing) of a gas channel of a gas turbine, has two component segments—4a, 4b—which are sealed against one another to reduce the leakage flow through a gap 5 between the component segments 4a, 4b by means of a sealing element 6 configured as a sheet-metal strip (a so-called sealing strip). The sheet-metal strip 6 extends between corresponding grooves 8a, 8b on the edges of the component segments 4a, 4b. The component segments 4a, 4b may be both a covering (fairing) as well as a gas channel wall part (panel). However, the disadvantage of this component 2, or this sealing device 6, is that impermeability is inadequate especially under changing operating conditions.
FIG. 2 shows a schematic lateral view of another example of a component 2 known from the prior art, in which the edges of its component segments 4a, 4b overlap. The component segments 4a, 4b are ground in the region of their overlapping locations (ground overlap). The sealing device 6 includes a clamping claw 7, which is fastened to the component segment 4a via a nut-and-bolt connection 9 and via which the component segments 4a, 4b are pressed together with virtually no play with a defined preload force. The component segments 4a, 4b are able to move relative to one another other in the circumferential direction without changing the gap. However, the manufacturing expense for this component 2 is substantial, whereby correspondingly high fabrication and maintenance costs are incurred. In addition, there is a high occurrence of wear.
A gas turbine with a gas channel is known from U.S. Pat. No. 5,451,116 A, which is also made or formed of segmented components (fairings and panels). The sealing surfaces of the adjacent component segments are pressed against each other, similar to the depiction in FIG. 2, by means of tripod plates.
The object of the present invention is creating a segmented component, which also has a lower leakage rate under changing operating conditions and in addition, can also be manufactured more cost-effectively. A further object of the invention is making available a gas turbine with such a component.
Advantageous embodiments with expedient further developments of the invention are disclosed in the respective dependent claims, wherein advantageous embodiments of the component are to be considered as advantageous embodiments of the gas turbine and vice versa.
A component, which has a lower leakage rate even under changing operating conditions and is also simpler and more cost-effective to manufacture, is created in accordance with the invention in that the sealing device has at least one brush seal. In this case, the wire pack of the brush seal produces a sealing effect in that inflowing gas is forced to flow through the wire pack of the brush seal. In doing so, this flow of gas causes a compression of the wire pack and thereby automatically increases the sealing effect of the brush seal by closing the free spaces between the wires. Basically, the wire packs of the brush seal are able to be deformed relatively easily so that a high sealing effect of the sealing device is reliably guaranteed even under changing operating conditions, e.g., due to fluctuating ambient temperatures and pressures and in the case of thermally or mechanically deformed contact surfaces. In contrast to the prior art, the component is also able to be used without a problem in high-temperature ranges, because no screwed connections or the like are required. In addition, brush seals are able to be mounted and replaced easily, thereby producing corresponding cost advantages in the production and repair of the component. Further cost advantages are produced because a reliable seal can also be produced between component segments having irregular surfaces. For example, the brush seal also makes it possible to reliably seal cast surfaces without post-processing and smoothing. In addition, brush seals have a very low weight as well as a low requirement for installation space, whereby the component is able to be adapted in a simpler way to the different requirement profiles and intended uses. Other advantages include low wear at the sealing point.
An advantageous embodiment of the invention provides that the brush seal includes a wire pack, which is wound around a core wire and fixed on the core wire by a clamping tube. Such a brush seal is flexible and can be manufactured simply and cost-effectively. Depending upon the intended use of the component, wires of the wire pack may be made, for example, of a metal or a metal alloy and/or of a non-metallic material such as aramid, whereby the sealing device is adaptable in an optimal way. In addition, the length of the wire pack may be varied in an especially simple manner so that it is possible to seal any spatially desired component segment geometries.
Additional advantages are produced if the wire pack of the brush seal is arranged at an angle between 0° and 80°, in particular between 30° and 60°, to the associated sealing surface thereof. In this case, particularly angles of 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75° or 80°, along with corresponding intermediate angles, are to be understood as an angle between 0° and 80°. In this case, the angle may be determined in both a clockwise and counterclockwise manner. This type of brush seal makes it possible to compensate especially well for thermally or mechanically induced relative movements of the component segments due to the pliability of the wires. In addition, a simple adaptability to different component segment geometries is produced because of this.
It is provided in another embodiment of the invention that the brush seal is arranged in sections in a groove of at least one component segment and/or rests laterally on at least one of the component segments. In this case, a groove permits an especially simple mounting and dismounting of the brush seal. In addition, sides surfaces of the groove may also be used as contact surfaces for the wire pack so that the brush seal seals reliably even under changing internal and external pressure conditions. As a result, the term “groove” should also be understood within the scope of the invention as a guide groove. Because the brush seal rests laterally on one of the component segments, relative movements between the component segments are able to be compensated for especially well since not the tips of the wires but the entire side surface of the wire pack of the brush seal is able to function as a sealing surface.
In another embodiment of the invention, the sealing device includes a holding element, in particular a holding plate, by means of which the brush seal is fixed on at least one of the component segments. In this connection, the brush seal is able to be fixed on the component simply and in an operationally reliable manner. In particular, a holding element configured as a holding plate constitutes an especially cost-effective means of fixing the brush seal at least indirectly.
Another advantageous embodiment of the invention provides that the holding element is fixed on a component segment and/or is arranged at least in sections in a groove of a component segment and/or wraps around the brush seal. This makes it possible for the holding element to be fastened quickly, flexibly and cost-effectively on the component or the component segment. For example, the holding element may be screwed or riveted to at least one component segment. In addition, the holding element is fixed frictionally in the groove of the component, for example, by a press fit. Alternatively or additionally, the holding element may be fastened to the component segment in question by simple bending or crimping.
A reliable sealing effect is ensured even with great pressure differences between the inside and outside of the component in another embodiment of the invention by the sealing device, including a guide element for supporting the wire pack of the brush seal.
Additional advantages are produced in that the sealing device includes a seal carrier on which the brush seal is fixed. This makes it possible to position the brush seal in an especially variable manner. The seal carrier may be screwed, riveted and/or welded to the associated component segment, for example.
Another advantageous embodiment of the invention provides that the seal carrier is fixed on one of the component segments. This constitutes a structurally simple possibility of also fastening the brush seal indirectly on the component or on the component segment.
An especially stable connection of the component segments along with a low leakage rate is achieved in another embodiment of the invention in that one of the component segments and the seal carrier form a groove, in which the adjacent component segment is arranged at least in sections. In other words, it is provided that the seal carrier and one of the component segments form a groove in the mounted state into which the component segment functioning as a sealing partner is inserted to mount the component.
Another advantageous embodiment of the invention provides for the component segments to be slid on top of one another and/or be inserted into one another and/or be arranged at a distance from one another. This permits an especially flexible connection of the two component segments as well as a simple adaptability of the geometry of the gap left between the component segments.
Another embodiment of the invention provides that the component segments are moveable relative to each other, wherein the brush seal is designed to seal the component segments against each other within a predetermined operating parameter range of the component. In this case, in the scope of the present invention, the term “movable” characterizes merely minor relative movements. In other words, the component segments of the component are to be considered as being essentially stationary in relation to each other. In contrast to component segments that are permanently connected with one another, e.g., welded, the component according to the invention however continues to permit certain relative movements between the individual component segments so that the development of thermally or mechanically induced stress is reliably prevented. The brush seal is designed in this case so that, taking all manufacturing tolerances and all permissible relative movements of the component segments into account, it still touches the contact surfaces of the component segments even in the most unfavorable operating case. The gap between the component segments is thereby reliably sealed over the entire permissible operating range of the component.
In a further advantageous embodiment of the invention, the component is configured as a covering part (fairing) and/or as a gas channel wall part (panel) and/or as a diffuser and/or as a guide vane assembly for a gas turbine. This makes it possible to achieve the aforementioned advantages such as, for example, good sealing effect even in the case of thermally or mechanically deformed sealing points, low wear at the sealing points, reduced thermally-induced stress, simple and cost-effective mounting, avoiding screwed connections in the high-temperature range, sealing even on rough surfaces without post-processing of the surfaces in question and reduced production costs even in the case of these sensitive gas turbine components that are relevant for safety. In addition, leakages at sealing points have a considerable negative impact on gas turbines so that improved sealing of the component segments according to the invention significantly increases the efficiency of the system.
A further aspect of the invention relates to a gas turbine, in particular an aircraft engine, having at least one component according to one of the foregoing exemplary embodiments. The embodiments and further developments presented in conjunction with the component according to the invention, as well as the advantages thereof, apply correspondingly to the gas turbine according to the invention.
The fact that the component forms a gas channel in a compressor area and/or in a turbine area of the gas turbine makes it possible for the efficiency of the gas turbine to be increased advantageously because of the reduced leakage flow through the gap between the component segments of the component.
Other features of the invention are disclosed in the claims, the exemplary embodiments as well as on the basis of the drawings. The foregoing features and combinations of features cited in the description, along with the features and combinations of features cited below in the exemplary embodiments, are not just applicable in the respectively disclosed combination, but also in other combinations or alone without leaving the scope of the invention.